1. Field
The present disclosure relates to constructing low-density parity-check (LDPC) codes from small template graphs called protographs. More in particular, it relates to methods for designing rate-compatible families of protographs of different rates, where a code at one rate is used as an original code and alternative rate codes are obtained by extending, puncturing, or performing other operations on the original code. Constraints on the resulting parity check matrices are used to ensure that the resulting alternative rate codes provide good performance.
2. Description of Related Art